LXR linux/drivers/media/rc/sir

   1/*
   2 * IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
   3 *
   4 * sir_ir - Device driver for use with SIR (serial infra red)
   5 * mode of IrDA on many notebooks.
   6 *
   7 *  This program is free software; you can redistribute it and/or modify
   8 *  it under the terms of the GNU General Public License as published by
   9 *  the Free Software Foundation; either version 2 of the License, or
  10 *  (at your option) any later version.
  11 */
  12
  13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15#include <linux/module.h>
  16#include <linux/interrupt.h>
  17#include <linux/kernel.h>
  18#include <linux/serial_reg.h>
  19#include <linux/ktime.h>
  20#include <linux/delay.h>
  21#include <linux/platform_device.h>
  22
  23#include <media/rc-core.h>
  24
  25/* SECTION: Definitions */
  26#define PULSE '['
  27
  28/* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
  29#define TIME_CONST (9000000ul / 115200ul)
  30
  31/* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
  32#define SIR_TIMEOUT     (HZ * 5 / 100)
  33
  34/* onboard sir ports are typically com3 */
  35static int io = 0x3e8;
  36static int irq = 4;
  37static int threshold = 3;
  38
  39static DEFINE_SPINLOCK(timer_lock);
  40static struct timer_list timerlist;
  41/* time of last signal change detected */
  42static ktime_t last;
  43/* time of last UART data ready interrupt */
  44static ktime_t last_intr_time;
  45static int last_value;
  46static struct rc_dev *rcdev;
  47
  48static struct platform_device *sir_ir_dev;
  49
  50static DEFINE_SPINLOCK(hardware_lock);
  51
  52/* SECTION: Prototypes */
  53
  54/* Communication with user-space */
  55static void add_read_queue(int flag, unsigned long val);
  56/* Hardware */
  57static irqreturn_t sir_interrupt(int irq, void *dev_id);
  58static void send_space(unsigned long len);
  59static void send_pulse(unsigned long len);
  60static void init_hardware(void);
  61static void drop_hardware(void);
  62/* Initialisation */
  63
  64static inline unsigned int sinp(int offset)
  65{
  66        return inb(io + offset);
  67}
  68
  69static inline void soutp(int offset, int value)
  70{
  71        outb(value, io + offset);
  72}
  73
  74/* SECTION: Communication with user-space */
  75static int sir_tx_ir(struct rc_dev *dev, unsigned int *tx_buf,
  76                     unsigned int count)
  77{
  78        unsigned long flags;
  79        int i;
  80
  81        local_irq_save(flags);
  82        for (i = 0; i < count;) {
  83                if (tx_buf[i])
  84                        send_pulse(tx_buf[i]);
  85                i++;
  86                if (i >= count)
  87                        break;
  88                if (tx_buf[i])
  89                        send_space(tx_buf[i]);
  90                i++;
  91        }
  92        local_irq_restore(flags);
  93
  94        return count;
  95}
  96
  97static void add_read_queue(int flag, unsigned long val)
  98{
  99        DEFINE_IR_RAW_EVENT(ev);
 100
 101        pr_debug("add flag %d with val %lu\n", flag, val);
 102
 103        /*
 104         * statistically, pulses are ~TIME_CONST/2 too long. we could
 105         * maybe make this more exact, but this is good enough
 106         */
 107        if (flag) {
 108                /* pulse */
 109                if (val > TIME_CONST / 2)
 110                        val -= TIME_CONST / 2;
 111                else /* should not ever happen */
 112                        val = 1;
 113                ev.pulse = true;
 114        } else {
 115                val += TIME_CONST / 2;
 116        }
 117        ev.duration = US_TO_NS(val);
 118
 119        ir_raw_event_store_with_filter(rcdev, &ev);
 120}
 121
 122/* SECTION: Hardware */
 123static void sir_timeout(unsigned long data)
 124{
 125        /*
 126         * if last received signal was a pulse, but receiving stopped
 127         * within the 9 bit frame, we need to finish this pulse and
 128         * simulate a signal change to from pulse to space. Otherwise
 129         * upper layers will receive two sequences next time.
 130         */
 131
 132        unsigned long flags;
 133        unsigned long pulse_end;
 134
 135        /* avoid interference with interrupt */
 136        spin_lock_irqsave(&timer_lock, flags);
 137        if (last_value) {
 138                /* clear unread bits in UART and restart */
 139                outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
 140                /* determine 'virtual' pulse end: */
 141                pulse_end = min_t(unsigned long,
 142                                  ktime_us_delta(last, last_intr_time),
 143                                  IR_MAX_DURATION);
 144                dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
 145                        last_value, pulse_end);
 146                add_read_queue(last_value, pulse_end);
 147                last_value = 0;
 148                last = last_intr_time;
 149        }
 150        spin_unlock_irqrestore(&timer_lock, flags);
 151        ir_raw_event_handle(rcdev);
 152}
 153
 154static irqreturn_t sir_interrupt(int irq, void *dev_id)
 155{
 156        unsigned char data;
 157        ktime_t curr_time;
 158        static unsigned long delt;
 159        unsigned long deltintr;
 160        unsigned long flags;
 161        int counter = 0;
 162        int iir, lsr;
 163
 164        while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
 165                if (++counter > 256) {
 166                        dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
 167                        break;
 168                }
 169
 170                switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
 171                case UART_IIR_MSI:
 172                        (void)inb(io + UART_MSR);
 173                        break;
 174                case UART_IIR_RLSI:
 175                case UART_IIR_THRI:
 176                        (void)inb(io + UART_LSR);
 177                        break;
 178                case UART_IIR_RDI:
 179                        /* avoid interference with timer */
 180                        spin_lock_irqsave(&timer_lock, flags);
 181                        do {
 182                                del_timer(&timerlist);
 183                                data = inb(io + UART_RX);
 184                                curr_time = ktime_get();
 185                                delt = min_t(unsigned long,
 186                                             ktime_us_delta(last, curr_time),
 187                                             IR_MAX_DURATION);
 188                                deltintr = min_t(unsigned long,
 189                                                 ktime_us_delta(last_intr_time,
 190                                                                curr_time),
 191                                                 IR_MAX_DURATION);
 192                                dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
 193                                        deltintr, (int)data);
 194                                /*
 195                                 * if nothing came in last X cycles,
 196                                 * it was gap
 197                                 */
 198                                if (deltintr > TIME_CONST * threshold) {
 199                                        if (last_value) {
 200                                                dev_dbg(&sir_ir_dev->dev, "GAP\n");
 201                                                /* simulate signal change */
 202                                                add_read_queue(last_value,
 203                                                               delt -
 204                                                               deltintr);
 205                                                last_value = 0;
 206                                                last = last_intr_time;
 207                                                delt = deltintr;
 208                                        }
 209                                }
 210                                data = 1;
 211                                if (data ^ last_value) {
 212                                        /*
 213                                         * deltintr > 2*TIME_CONST, remember?
 214                                         * the other case is timeout
 215                                         */
 216                                        add_read_queue(last_value,
 217                                                       delt - TIME_CONST);
 218                                        last_value = data;
 219                                        last = curr_time;
 220                                        last = ktime_sub_us(last,
 221                                                            TIME_CONST);
 222                                }
 223                                last_intr_time = curr_time;
 224                                if (data) {
 225                                        /*
 226                                         * start timer for end of
 227                                         * sequence detection
 228                                         */
 229                                        timerlist.expires = jiffies +
 230                                                                SIR_TIMEOUT;
 231                                        add_timer(&timerlist);
 232                                }
 233
 234                                lsr = inb(io + UART_LSR);
 235                        } while (lsr & UART_LSR_DR); /* data ready */
 236                        spin_unlock_irqrestore(&timer_lock, flags);
 237                        break;
 238                default:
 239                        break;
 240                }
 241        }
 242        ir_raw_event_handle(rcdev);
 243        return IRQ_RETVAL(IRQ_HANDLED);
 244}
 245
 246static void send_space(unsigned long len)
 247{
 248        usleep_range(len, len + 25);
 249}
 250
 251static void send_pulse(unsigned long len)
 252{
 253        long bytes_out = len / TIME_CONST;
 254
 255        if (bytes_out == 0)
 256                bytes_out++;
 257
 258        while (bytes_out--) {
 259                outb(PULSE, io + UART_TX);
 260                /* FIXME treba seriozne cakanie z char/serial.c */
 261                while (!(inb(io + UART_LSR) & UART_LSR_THRE))
 262                        ;
 263        }
 264}
 265
 266static void init_hardware(void)
 267{
 268        unsigned long flags;
 269
 270        spin_lock_irqsave(&hardware_lock, flags);
 271        /* reset UART */
 272        outb(0, io + UART_MCR);
 273        outb(0, io + UART_IER);
 274        /* init UART */
 275        /* set DLAB, speed = 115200 */
 276        outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
 277        outb(1, io + UART_DLL); outb(0, io + UART_DLM);
 278        /* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
 279        outb(UART_LCR_WLEN7, io + UART_LCR);
 280        /* FIFO operation */
 281        outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
 282        /* interrupts */
 283        /* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
 284        outb(UART_IER_RDI, io + UART_IER);
 285        /* turn on UART */
 286        outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, io + UART_MCR);
 287        spin_unlock_irqrestore(&hardware_lock, flags);
 288}
 289
 290static void drop_hardware(void)
 291{
 292        unsigned long flags;
 293
 294        spin_lock_irqsave(&hardware_lock, flags);
 295
 296        /* turn off interrupts */
 297        outb(0, io + UART_IER);
 298
 299        spin_unlock_irqrestore(&hardware_lock, flags);
 300}
 301
 302/* SECTION: Initialisation */
 303static int sir_ir_probe(struct platform_device *dev)
 304{
 305        int retval;
 306
 307        rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
 308        if (!rcdev)
 309                return -ENOMEM;
 310
 311        rcdev->input_name = "SIR IrDA port";
 312        rcdev->input_phys = KBUILD_MODNAME "/input0";
 313        rcdev->input_id.bustype = BUS_HOST;
 314        rcdev->input_id.vendor = 0x0001;
 315        rcdev->input_id.product = 0x0001;
 316        rcdev->input_id.version = 0x0100;
 317        rcdev->tx_ir = sir_tx_ir;
 318        rcdev->allowed_protocols = RC_BIT_ALL_IR_DECODER;
 319        rcdev->driver_name = KBUILD_MODNAME;
 320        rcdev->map_name = RC_MAP_RC6_MCE;
 321        rcdev->timeout = IR_DEFAULT_TIMEOUT;
 322        rcdev->dev.parent = &sir_ir_dev->dev;
 323
 324        setup_timer(&timerlist, sir_timeout, 0);
 325
 326        /* get I/O port access and IRQ line */
 327        if (!devm_request_region(&sir_ir_dev->dev, io, 8, KBUILD_MODNAME)) {
 328                pr_err("i/o port 0x%.4x already in use.\n", io);
 329                return -EBUSY;
 330        }
 331        retval = devm_request_irq(&sir_ir_dev->dev, irq, sir_interrupt, 0,
 332                                  KBUILD_MODNAME, NULL);
 333        if (retval < 0) {
 334                pr_err("IRQ %d already in use.\n", irq);
 335                return retval;
 336        }
 337        pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);
 338
 339        retval = devm_rc_register_device(&sir_ir_dev->dev, rcdev);
 340        if (retval < 0)
 341                return retval;
 342
 343        init_hardware();
 344
 345        return 0;
 346}
 347
 348static int sir_ir_remove(struct platform_device *dev)
 349{
 350        drop_hardware();
 351        del_timer_sync(&timerlist);
 352        return 0;
 353}
 354
 355static struct platform_driver sir_ir_driver = {
 356        .probe          = sir_ir_probe,
 357        .remove         = sir_ir_remove,
 358        .driver         = {
 359                .name   = "sir_ir",
 360        },
 361};
 362
 363static int __init sir_ir_init(void)
 364{
 365        int retval;
 366
 367        retval = platform_driver_register(&sir_ir_driver);
 368        if (retval)
 369                return retval;
 370
 371        sir_ir_dev = platform_device_alloc("sir_ir", 0);
 372        if (!sir_ir_dev) {
 373                retval = -ENOMEM;
 374                goto pdev_alloc_fail;
 375        }
 376
 377        retval = platform_device_add(sir_ir_dev);
 378        if (retval)
 379                goto pdev_add_fail;
 380
 381        return 0;
 382
 383pdev_add_fail:
 384        platform_device_put(sir_ir_dev);
 385pdev_alloc_fail:
 386        platform_driver_unregister(&sir_ir_driver);
 387        return retval;
 388}
 389
 390static void __exit sir_ir_exit(void)
 391{
 392        platform_device_unregister(sir_ir_dev);
 393        platform_driver_unregister(&sir_ir_driver);
 394}
 395
 396module_init(sir_ir_init);
 397module_exit(sir_ir_exit);
 398
 399MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
 400MODULE_AUTHOR("Milan Pikula");
 401MODULE_LICENSE("GPL");
 402
 403module_param_hw(io, int, ioport, 0444);
 404MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
 405
 406module_param_hw(irq, int, irq, 0444);
 407MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
 408
 409module_param(threshold, int, 0444);
 410MODULE_PARM_DESC(threshold, "space detection threshold (3)");
 411